N dimethyl p phenylenediamine

Poly(vinylpirrolidone) (PVP) with molecular weight of 40000 g/mol purchased from Merck was used as pore former. 1-methyl-2-pyrolidone (NMP), procured from Merck, and distilled water were applied as solvent and non-solvent, respectively. PES (Ultrason E6020P) with molecular weight of 58000gr/mol supplied from BASF was used as polymer in the casting solution. Brij^®S100 (poly(oxyethylene (100) stearyl ether)) with the HLB = 18 purchased from Aldrich was applied as surfactant. Amoxicillin (pKa = 2.7) [6 (link)] was obtained from Dana pharmaceutical company. The chemical structure of PES, Brij^®S100 and amoxicillin are illustrated in Figure 1. N, N-dimethyl-p-phenylenediamine, potassium hexacynoferrate (III), NH₃ and NaOH were bought from Merck.

Polyethersulfone (Ultrason E6020P, MW = 58,000 g/mol) supplied from BASF company was employed as basis polymer of the membranes. N-methyl-2-pyrrolidone (>99.5 %) and polyvinylpyrrolidone (PVP K 40) purchased from Merck (Germany) were used as solvent and pore former, respectively. Surfactant additive, Brij 58 (polyethylene glycol hexadecyl ether, C₅₆H₁₁₄O₂₁) with the hydrophilic-lipophilic balance (HLB) =16 was bought from Sigma–Aldrich. Distilled water was used as nonsolvent. Amoxicillin (C₁₆H₁₉N₃O₅S) and ceftriaxone (C₁₈H₁₈N₈O₇S₃) were procured from Dana pharmaceutical company (Tabriz, Iran). Table 1 summarizes characteristics of these pharmaceuticals. N, N-dimethyl-p-phenylenediamine, potassium hexacynoferrate (III), iron (III) nitrate.9H₂O, NH₃ and NaOH were purchased from Merck.Table 1

Characteristics of the selected pharmaceuticals

Molecular Structure	Mw, g mol−1	Dissociation constants (Pka)
Amoxicillin	365.4	2.4, 7.31, 9.53 [57 ]
Ceftriaxone	554.58	3, 3.2, 4.1 [58 ]